Looking at Babbage and Ada who looked very interested, Xu Yun shook his head helplessly.
He sighed secretly in his heart and led the two of them towards the table:
"Please come with me."
As soon as he approached the edge of the table, Babbage's eyes were attracted by the vacuum tube on the table.
More than half an hour ago.
Babbage and Ada were doing research in the attic, when Ada's husband, Count Lovelace, appeared outside the door with Kirchhoff.
Then Kirchhoff, as the spokesperson of the sponsor's father, gave Babbage and Ada a master's task:
Elbow, come to school with me!
However, due to time constraints.
Kirchhoff simply mentioned Wheat's idea, which was that there was such a special vacuum tube that could replace the gear.
After saying that, he rushed to the laboratory with Babbage and Ada.
Therefore, Babbage only roughly knew that there was such a test tube in the laboratory that might help him, but he did not know the specific appearance and principle.
But on the other hand.
As a parts professional who has been in contact with electronic components day and night for almost thirty years, Babbage was very sensitive to various components.
So the moment I saw the electron tube.
Babbage had an inexplicable premonition in his heart:
This thing must be of great use to you!
Xu Yun on the side threw a look at Xiaomai, the meaning was obvious:
You have to explain it yourself.
Seeing this, Xiaomai nodded, came to Babbage's side, and said:
"Mr. Babbage, I heard that the Analytical Engine you designed used gears to store data?"
Babbage raised his head and glanced at Wheat. Although he had never met Wheat before, he still understood one thing:
It is absolutely extraordinary to be able to conduct experiments with Faraday, Gauss, Weber and the other three.
Either they are close blood descendants, or they are future stars with unlimited potential.
Therefore, he was not angry at Xiaomai's somewhat abrupt question. Instead, he smiled politely and answered patiently:
"That's right, Ada and I designed a dense-toothed gear... Oh, by the way, I'm carrying it with me now."
As he spoke, Babbage took off a backpack from behind and started rummaging through it.
in the past few years.
In order to find interested investors, Babbage was basically like the vendors who sold compact discs and sunglasses in the 1990s. He carried some sample parts with him anytime and anywhere, just to explain his invention in more detail.
About ten seconds passed.
Babbage took out a gear from it, handed it to Xiaomai, and said:
"This classmate, this is it. It's a bit heavy. Just hold it steady."
Wheat took over the gear and looked at it carefully.
This is a standard cast iron gear, which looks about the size of a palm, with tiny tooth holes densely distributed on it.
While Wheat was observing the gears, Babbage also took the initiative to explain:
"A gear has 118 teeth and can store ten fifty-digit numbers. After every seven gears form a number axis, calculations within ten digits can be performed."
Xu Yun glanced at him lightly, but did not reveal his lie.
What Babbage meant by "calculations to within ten digits" actually meant addition and subtraction, and could only contain up to three decimal places.
If we discuss multiplication, division or even square roots, five-digit numbers are almost at the top.
Of course.
This refers to the equipment that has been completed so far, not the expectations - after all, there is no upper limit to the pie. If you really want to brag, it can be as high as fifty figures.
Kirchhoff on the side was aroused by these words. This man is also a circuit enthusiast:
"Mr. Babbage, judging from the workmanship, the cost of a gear should be quite high, right?"
Babbage took the gear back from Wheat's hand, turned it up and down, and sighed:
"Yes, the number of teeth, 118, cannot be divisible by 360 degrees, so the accuracy requirements are extremely high. It can even be said that there is no real technical upper limit."
"Currently, on average, the cost of a gear is about 0.2 pounds."
Kirchhoff opened his mouth and smacked his tongue:
"It's so expensive..."
Mentioned earlier.
The purchasing power of one pound these days is roughly equivalent to 900 yuan in later generations, and 0.2 pounds is almost 180 to 200 yuan.
In later generations, a gear with 160 teeth and an outer diameter of 162mm was sold for about 30 yuan, and the cost was even lower.
The reason for this huge expenditure is mainly related to today's forging process. A considerable part of the so-called average manufacturing cost is the expenditure on modules.
Not to mention that the craftsmanship required for the original module is complicated, and in the absence of large-scale pressure equipment, even if you can forge a suitable module, it will not take long.
If this happens over and over again, the expenses will naturally increase.
It's no wonder that Babbage failed to start a business continuously - Clement's rebound was certainly the main reason, but the expenditure on these equipment was also a big pit that could not be ignored.
For example, Babbage's Difference Engine No. 2, which he never completed until his death, required more than 4,300 gears.
Even if there is no work damage in the whole process, the investment in light gears will be close to 900 pounds.
Then Maimai asked Babbage some other questions, and having a rough idea, he said to Babbage:
"So Mr. Babbage, in your design, data storage...or handover is actually the most costly link?"
Babbage nodded, looked at Ada next to him, and sighed:
"Yes, compared to Ada's algorithm writing, data storage is undoubtedly much simpler - it only needs enough gears."
"But on the other hand, it is the most expensive project, and if anything goes wrong, all the progress will be lost."
After listening to Babbage's words quietly, Xiaomai snapped his fingers briskly and said to Babbage:
"That's it, I understand!"
"Mr. Babbage, I am now certain that Xiao Yanguan will definitely be able to help you!"
Finished.
He led Babbage to the table and picked up a vacuum tube.
This chapter is not finished yet, please click on the next page to continue reading the exciting content! To be precise.
It is a vacuum tube filled with mercury.
Then Mai held the end of the tube, put it in front of his eyes, and said to Babbage:
"Mr. Babbage, you should know that sound waves propagate slower in mercury than electrical signals propagate in wires, right?"
Babbage nodded.
Compared with the speed of light previously calculated by Xu Yun, the scientific and technological level in 1850 had already thoroughly studied sound waves - even in the original history.
At this time, the scientific community not only knew that sound waves propagated at different speeds in different media, but also mastered their specific values.
For example, the speed in the air is relatively slow, about 340 meters per second.
It is faster in solids and liquids.
For example, the propagation speed in a copper rod is 3750 meters per second, and the propagation speed of mercury is about 1450 meters per second.
But no matter how fast the sound waves are, they are still 18,000 times slower than the propagation speed of electrical signals.
Seeing that Babbage was communicating well, Xiaomai continued to explain:
"In that case, I have an idea..."
"Can we connect a closed wire to the outside of this Xiao Yan tube filled with mercury, and then connect multiple Xiao Yan tubes in series to form a closed circuit?"
"Then use the time difference between internal and external information dissemination as the principle, and add some other small means to replace gears and achieve the effect of information storage?"
Babbage's eyes widened as he listened, while Xu Yun's expression on the side was...
Broken.jpg.
how to say.......
After what Wheat said before.
Xu Yun was almost mentally prepared for the current situation.
After all, Xiaomai's idea is obviously towards mercury delay line memory.
That's right.
Mercury delay line memory.
As said before.
If the history of computers is regarded as the protagonist of a novel, then the history of the development of memory is undoubtedly a standard heroine - the one who appears in the second chapter.
Except for the "adding machine" originally invented by Pascal, a Gaulo, which did not require storage (because it was enough to just write down the answer), all other computer development periods were inseparable from memory.
The earliest data storage medium in history was called punched card, also known as punched card.
It is a piece of cardboard that can store data. It can record numbers, letters, special symbols and other characters by punching holes at predetermined positions.
The punch hole first appeared in 1725 and was invented by Gauls Bougio.
At first it was used to store information for controlling the working process of textile machines, and then it went wrong:
This thing was once used as a storage device to count the number of slaves, and it would probably not get back on track until around 1900. It is not recommended to laugh at it, because in addition to black slaves, the statistical objects also include Chinese workers.
By 1928, IBM introduced a punch hole with a specification of 190x84mm, using rectangular holes to increase storage density.
This punch hole can store 80 columns x 12 rows of data, which is equivalent to 120 bytes.
After the punch hole is the command tape. This thing is somewhat similar to the dotting timer in the high school laboratory, which can be regarded as a symbol of the era of mechanized storage technology.
After punching holes and punching holes, we entered the real storage development stage of modern computers.
The first storage device that appeared had a pretty nice name, called magnetic drum.
The earliest magnetic drum looked similar to a massage stick. It would make a buzzing sound when operating, and sometimes it would spray water. It rotated very quickly, and often needed to add water for cooling.
And after the magnetic drum.
What comes on the scene is the mercury delay line memory.
The principle of mercury delay line memory is similar to what Wheat said. The core is one:
The difference in travel time between sound waves and electrical signals.
Of course.
What we are talking about here are electrical signals, not electrons.
The movement speed of electrons in metal wires is very, very slow. In some cases, they may even move a few centimeters per second.
The speed of the electrical signal is actually the speed of the field, which depends on the dielectric constant of the material.
Generally speaking, the electrical signal of a copper wire is about 230,000 kilometers per second.
The transmission time difference between sound waves and electrical signals is huge, which provides a theoretical basis for the emergence of mercury delay storage technology:
One end of it is an electroacoustic conversion device, which converts electrical signals into sound waves that propagate in mercury.
Because the propagation speed is relatively slow, it takes one to several seconds for the sound wave signal to propagate to the other end.
The other end is the acoustic-to-electrical conversion device, which converts the received acoustic signal into an electrical signal again, and then inputs the processed signal to the electro-acoustic conversion end again.
This forms a closed loop and the signal can be stored in the mercury tube.
in the original history.
Humanity's first universal automatic computer UNIVAC-1 used this technology, and the time difference was about 960ms.
This idea is undoubtedly far ahead of this era, but it is still better than the extreme situation Xu Yun thought about - after all, Xiaomai is just a wall hanging, and has not yet obtained the GM version development rights.
As for mercury delayed storage technology, what about the future...
It is the William tube, the magnetic core and now the magnetic disk.
As for the future trend, it is the DNA storage technology that Xu Yun has obtained before.
His eyes returned to reality.
Wheat's idea quickly attracted everyone's attention, and many elders, including Ada and Riemann, gathered around the table again.
Babbage was the person with the strongest manual skills on site, so while he was excited, he quickly thought of the practical issues:
"Classmate Maxwell, although your idea is very good, how can we ensure that the time difference is extended as much as possible?"
"If it is just a test tube of a few centimeters or more, then there is almost no time difference between sound waves and electrical signals - at least there is not enough time difference to store data."
Ada also nodded.
In a test tube of more than ten centimeters, the sound wave will basically arrive in seconds. Although there is still a time difference between the sound wave and the electrical signal, it obviously cannot be used.
This chapter is not over yet, please click on the next page to continue reading! However, Xiaomai obviously had a plan for this, and he smiled confidently at Babbage:
"Mr. Babbage, I have actually thought about this issue before."
"First of all, we can expand the length of the Xiao Yan tube. Its material is only transparent glass. In the case of mass production, the cost difference between ten centimeters and one meter is actually not very big."
"In addition, we can add some other small equipment, such as..."
"The detector invented by Mr. Luo Feng when he was testing electromagnetic waves."
Babbage blinked and asked confusedly:
"Detector?"
Xiaomai nodded and took out a small object of about ten centimeters from the drawer - this object was the iron filing detector Xu Yun had invented before.
Smart classmates should all remember it.
When verifying the photoelectric effect, Xu Yun used two key detection methods:
He first used the standing wave method to form a standing wave in the house, then used a prepared iron filing detector to test the peaks and troughs of the waves, and finally calculated the wavelength of the electromagnetic waves.
The principle of the detector is very simple:
When the photoelectric effect does not occur, the iron filings are loosely distributed.
The entire detector is equivalent to a circuit break, and the meter will not display current.
And once electromagnetic waves are detected.
The iron filings will move and gather into a ball, acting as a conductor and activating the voltmeter.
The closer to the peak or trough of the wave, the more iron filings will condense, and the value on the meter will be larger.
If the iron filings in other positions are less condensed, the electric value will be lower or even 0.
After introducing the principle of the geophone designed by Xu Yun to Babbage, Xiaomai said:
"Mr. Babbage, this is what I think. We can install one or several small components based on the principle of a detector at the signal access port."
"Then the signal strength is controlled, and the electrical signal transmission in the external wire is periodically limited, somewhat similar to... a wave."
"The Sword Comes"
"In this way, the time difference should be extended to a certain extent, and it may even be helpful for subsequent calculations."
When Babbage heard this, he immediately fell into deep thought.
The principle described by Wheat is somewhat similar to the pulse current of later generations, but the concept of pulse would not officially appear until 1936 - just like William Whewell proposed the title of scientist, many modern words or characters that seem sparse and ordinary,
In fact, it does not exist innately.
Therefore, today's wheat cannot directly use the concept of pulse to explain it to Babbage, and successfully helped a certain writer write a few words.
"Wave..."
Babbage thought carefully for a while, touched his chin and said:
"It is indeed feasible... In that case, Maxwell, can we try it now?"
Wheat raised his head and glanced at Faraday, who nodded cheerfully:
"They are all available in the equipment laboratory, of course."
Mentioned earlier.
The vacuum tube designed by Faraday at Cambridge can be split and connected in order to increase the observation effect.
If necessary, you can even infinite Human Centipede.
Therefore, the extra-long test tubes that Wheat mentioned only need a little time to be spliced together.
As for the detector...
When Xu Yun measured standing waves, he basically had one person per hand, so the number was naturally not too small.
More than ten minutes later.
A simple vacuum tube, nearly two meters long, filled with mercury inside and made of metal shavings and wires outside, was assembled.
Wheat then added a set of polarizers to it, and connected a powered timer to the end of the vacuum tube.
That's right.
Chronograph.
As we all know.
Space and time constitute our world.
Since the birth of mankind, human exploration of space and time has never stopped.
Even primary school students in future generations will know this.
In 1850, humans had completed their voyage around the earth and discovered all the known landmass. At most, some small islands had not yet been included in the map.
But when it comes to the accuracy of time, many people may have a vague concept:
There are definitely seconds, but how accurate is it?
Or 1/2 second?
1/5 second?
Or 1/10 of a second?
Unfortunately, all of the above are too conservative.
The concept of "timekeeping" actually achieved development in the early 19th century that surprised many people in later generations.
The first chronograph in history appeared in 1815, and its inventor was Louis Moinet—yes, the founder of Louis Moi in later generations.
The chronograph he invented can oscillate several times per hour and is accurate to 1/60 of a second.
The original history was like this, let alone 1850 when the timeline changed.
Today's timers can be accurate to 1/140th of a second, which is the centisecond level, but there is still a lot of difference in milliseconds.
On the basis of this accuracy, Wheat added a balance spring to ensure that the timer will instantly trip and cut off power as soon as it receives an electrical signal.
After everything is ready.
Wheat came to the table and pressed the power switch.
With the switch pressed.
An electromotive force was quickly generated inside the Rumkov coil.
The invisible electrical signal follows the electric field and instantly crosses to the other end of the coil, and then enters the interior of the vacuum tube.
clatter--
It takes less than the blink of an eye.
The circuit connected to the balance spring tripped, and a number was clearly displayed on the timer:
0.09 seconds.
This number represents the time it takes for the electrical signal to travel through the interior of the mercury. Whether or not the information can be transmitted is another matter.
And according to the ideas of Wheat and Babbage.
This time difference must be at least 0.5 seconds or more.
That is to say...
Relying on a pulse voltage alone is completely unable to achieve the expected effect.
"It failed..."
Think of this.
Wheat couldn't help scratching his hair, and then...
Looking at Xu Yun:
"Classmate Luo Feng..."
Undecided in times of trouble, classmate Luo Feng.
...
Note:
I came back today and adjusted my biological clock. The updates will probably be in the early hours of the morning these two days.
